Pneumatic mechanism for rendering a vacuum cleaner inoperative if no bag is in place



' Nov. 3, 1959 Filed Dec. 26, 1956 J. T. FERRARIS PNEUMATIC MECHANISM FOR RENDERING A VACUUM CLEANER INOPERATIVE I F NO BAG IS IN PLACE 35heets-Sheet 1 N INVENTOR. I JOHN T Fume/s HIS ATTORNEY Nov. 3, 1959 JQ -r. FERRARIS 2,911,062

PNEUMATIC MECHANISM FOR RENDERING A VACUUM CLEANER INOPERATIVE IF NO BAG IS IN PLACE F11 ed Dec. 26, 1956 3 Sheets-Sheet 2 INVENTOR.

.w I Jon/v TFkzeaz/s ZZWAM HIS ATTORNEY J. T. FERRARIS 2,911,062 PNEUMATIC MECHANISM FOR RENDERING A VACUUM CLEANER INOPERATIVE IF NO BAG IS IN PLACE 3 Sheets-Sheet 3 8 4 Q m R s 8 No Q 3 h QT 3 mi 3? w @w 1 K vw ..O...

Q n N. v a 1- v Q vh Nb vm mm MN \Q M hm am MN \Q mm Qfi Nov. 3, 1959 Fild D60. 26, 1956 INVEN TOR. JOHN Z'Fmenen H16 ATTOFNEX PNEUMATIC MECHANISM FOR RENDERING A VACUUM CLEANER INOPERATIVE IF NO BAG IS IN PLACEv John T. Ferraris, Stamford, Conn., assignor to Electrolux Corporation, Old Greenwich, Conn., a corporation of Delaware Application December 26, 1956, Serial No. 630,505 4 Claims. (Cl. 183-37) My invention relates to vacuum cleaners and more particularly to vacuum cleaners of the tank or canister type in which the dust bag is concealed from view within the casing of the cleaner.

With cleaners of this type it is necessary to periodically remove the dust bag in order to empty it or, if it is a disposable bag, to dispose of it with its contents. In either case it sometimes occurs that the operator forgets to replace the cloth bag or to insert a new disposable bag, with the result that the dirt drawn into the cleaner during subsequent operation of the machine fouls the fan and motor and, if the machine is not provided with a filter, a large percentage of the dirt passes through the cleaner and is discharged into the 'air'in the room.

If the cleaner is of a type using a disposable bag having a relatively stifl air impervious cardboard disc formed with a small inlet opening the removable cover of the cleaner may be so constructed that it does not seal the dust bag compartment, the aforementioned cardboard disc being relied upon for this purpose. Consequently, if no dust bag is in position within the cleaner, the dust bag compartment will not be sealed, but will be open to the atmosphere so that if the motor-fan unit is operated relatively clean air will be drawn directly into the dust bag compartment and little or no flow will take place through the hose, inasmuch as the latter path offers a much greater resistance to flow. Hence, while the motor-fan unit may be operated, no dirt will be drawn into the cleaner. Such arrangements are shown in Patent No. 2,567,221, issued September 11, 1951, to G. E. Lofgren and Patent No. 2,641,330, issued June 19, 1953, to Lofgren, Lampe and myself.

However, with an arrangement of this nature it is not possible to use a permanent cloth bag having a wide open mouth, as is preferable for easy emptying, as the dust bag compartment would not be sealed when such a bag is in place. Accordingly, it is an object of my. in-. vention to provide an arrangement whereby either a cloth dust bag or a disposable dust bag'may be employed,

together with means for preventing operation of the vacuum cleaner in the event .no bag is placed therein. More particularly, my invention includes peumatically operated means for releasing the latch which normally secures the front cover in closed position, together with means responsive to the absence of a dust bag for connecting the penumatic means to the fan so that, if a bag is not in position, as soon as the motor-fan unit is started the suction produced thereby is communicated to the pneumatic means so as to cause it to immediately open the latch. On the other hand, if either a disposable paper bag or a cloth bag is in position within the cleaner, communication between the fan and the pneumatically operated means is interrupted. The pneumatically operated means may be provided solely for the above purpose or it may be also actuated in response to a predetermined pressure drop through. the dust separating member so as to automatically stop the operation of the cleaner when the bag requires emptying.

Further objects and advantages of my invention will be apparent from the following description considered in connection with the accompanying drawings which forma part of this specification and of which:

Fig. lis a view partially in cross-section of a vacuum cleaner including one embodiment of my invention andshowing the cleaner with a disposable bag in placetherein;

Fig. 2 is a cross-sectional view similar to Fig. 1, but on a larger scale and showing a cloth bag in the cleaner;

Fig. 3 is a cross-sectional view similar to Fig. 2, butshowing the cleaner with no bag in position;

Fig. 4 is a cross-sectional view of another embodiment of my invention with a disposable bag in the cleaner;

Fig. 5 is a cross-sectional view similar to Fig. 4, but showing a cloth bag; and

Fig. 6 is a similar cross-sectional view, but showing no bag in the cleaner.

Referring more particularly to Figs. 1 through 3, reference character 10 designates generally the housing of a tank type vacuum cleaner, in one end of which is located a motor-fan unit 12 having an inlet 14; The space 16 within the housing 10 to the left of the motor-fan unit, as viewed in Fig. 1, is a dust bag compartment in which is disposed a bag supporting member 18 formed with a large number of perforations 20. The open end of member 18 is secured to a ring 22 fastened to the open end of casting 10.

A cover or closure member 24 is pivotally and removably secured to the ring 22 by means of a hinge 26. A latch member 30 is pivotally mounted at 32 in the cover diametrically opposite from the hinge 26 and is provided with a spring 34 urging it in a counter-clockwise direction, as viewed in Figs. 1 through 3. The upper part of ring 22 is provided with a pair of ears 36 extending forwardly therefrom and between which is disposed a keeper in the form of a bar or pin 38. As seen in Figs. 1 and 2, the latch 30 is in engagement with the pin 38 so as to hold the cover closed.

Latch 30 has a button portion 40 which extends outwardly through an opening in the cover 24 so as to be accessible for manual operation. The latch 30 also has attached thereto an arm 42 which is engaged by a stem 44 connected to a diaphragm 46 which constituted one wall of a diaphragm chamber 48 formed in the cover. The interior of chamber 48 is connected by means of a conduit 50 with a space 52 within the housing of a differential pressure responsive device designated generally by reference character 54.

This device includes a pressure responsive diaphragm 56, the right-hand side of which, as viewed in Fig. 1, is subjected through a conduit 58 to the pressure existing within an inlet conduit 60 carried by the front cover. The other side of the diaphragm 56 is subject to the suction produced by the motor-fan unit and communicated through the dust bag compartment 16, a short conduit 62 carried by the ring 22 and a conduit 64 in the cover 24. The ends of conduits 62 and 64 are in sealing relationship with each other when the cover 24 is closed. The diaphragm 56 is biased to the right by means of a spring 66. A valve member 68 is slidably mounted in the device 54 and is attached to a valve stem 70 which is disposed so as to be contacted by the diaphragm when the latter moves to the left. A spring 72 tends to seat the valve 68. As previously described, high suction from the fan will be communicated to the left side of the diaphragm 56 and, if the valve 68 is opened by movement of the diaphragm to the left, this suction will be communicated through the space 52 and the conduit 50 to the diaphragm chamber 48, thus moving the diaphragm 46 to the left so as to pivot the latch 30 in a clockwise direction to thereby disengage it from the keeper 38. The latch. 30,. diaphragm. chamber 48 and control devices 54 are enclosed within the cover 24 by a plate 73.

This vacuum cleaner: designed: to employ either a disposable paper; dust bag ]?"31 cloth bag. which may be emptied and used repeatedly, In1Fig.. 1 there is shown a disposable: bag. designated generally by reference charactor. 74. This bag includes a. substantially rigid air impervious.v cardboard disc 76: to which is: secured a bag portion 78 made. of pervious paper so that the air may pass therethrough while the dust is retained therein.- The disc: 76 isformed with a centrally located aperture 79 through which extends. the inlet conduit 64 when the cover, is closed. Plate 7320f the' cover preferably carries a gasket member 80 which surroundsthe inlet conduit 6.0:: and: bears against: the disc 76st) as to-hold the outer periphery or flange portion-of. the latter against a seat formed by a gasket 82catried1by: thearing 22'. A gasket 83 carried by plates 73 contacts the fl'ange portion around its, outer edge and aids. in: holding it against gasket. 82.

In Fig. 2 there is shown a cloth bag 106 secured? to a metal ring 168 having an outwardly extendingflange portion 110, which is clamped between gaskets 82f and 83:

The outer end' of conduit 60- is formed as one part of a. separable coupling so that a' flexible hose carrying the other, part. of: the: coupling may be connected there-- to, Operation of the motor-fan unit 12 serves to draw air in through the hose and conduit 60 to the interior of the dust bag, which separates from theair. any dirt entrainedv therewith, the: clean air passing through the pervious material of the bag.

Secured to the upper side of housingis abracket 84, which is. disposed between the casing and a trim piece 85. This bracket is formed with a rear upwardly extending arm. 9% having a slot formed therein. A rod 94- extends through the "slot and through an aligned opening: formed in ring 22. A coil spring 96 isdis posed-around rod94" and is confined between arm90' and a collar or flange 98 formed on the rod. Consequently,

this spring. tends to move the rod 94 tothe left, as

viewed in Fig. 1. The right-hand end of the rod94 is connected to the operating member 1th? of an electric switch,.the arrangement being suchthat when the'rodis moved to the left. under the influence of spring 96, the rod/moves the member 100to the off position; The left end of the rod which projects through the opening ofthe ring 22 isdi'sposed so as to'contact aprojectionltll" on' the cover 24 whenithe latte'r'isclosed, the closing of the cover pushing the: rod to the right so as to compress the spring 96. Hence; when: the cover is released by the disengagement of latch: 3G from'the'keeper 28; the rod 94 under the influence of spring 96 startstopi vo't" the" cover. toopen' position.

Connectedito. diaphragmchamber 48 is-aconduit 102 which leads to a resilient funnel-shaped member 104 -carricd by the: plate 73; This-funneL shaped member is so positioned. that. if a disposable dust bag is in position withinthe-cleanert-he carboard disc 76 thereof serves to close: the end of the. member" as is shown in' Fig; 1. Likewise, if the clothbag 106 is-in the cleaner, as shown in Fig. 2, the; metal: flange 110- of ring- 108 serves to block the, endofmember' 104.- However, if there is no dust separatingmember in the cleaner, the-ei1d of member 104 is. open and is in communicationwith the dust bag:compartment 16', as is shown in Fig. 3. Filter disc 76- hence act-s inv conjunction with member 104" as a simple. valve for controlling 'fiow through conduit 102 from chamber. 48 toi the dust bag compartment 16 Thus, if-: no hagisiinthe cleaner, the front'cover'24" may beclosed and the latch willengage the-keeper 38 soasto securethe cover iniclosed position; However, as soon as the motor-fan unit is-started, the suction-pro= duced. thereby. is communicated" through the dust bag.

compartment to the member 104- and thence through conduit 102 to diaphragm chamber 48: This causes the diaphragm 46 to be movedto the left, as viewed in the figures, thus pivoting latch so as to disengage it from the keeper. The rod 94, under the influence of spring 96 moves to the left, opening cover 24 and stopping the motor by opening switchlttt). Hence, although the cover may be closed with no bag in the cleaner, operation of the motor-fan unit immediately releases the front cover latch; thus permitting the cover to openand the motor to be shut oif and hence prevents continued operation of the cleaner. On the other hand, if either a disposable dust bag or acloth: bag is in the cleaner, the end of member 104 is sealed by the cardboard disc 76 or the metal. flange 110, respectively, and consequently the suction resulting from'op'eration of the m'o'tor fan unit is not communicated through. the conduit-162 to the diaphragm chamber, and hence the latch is not released.

Continued operation of the cleaner with a dust bag in position results" in accumulation of dirt within the bag which increases the pressure drop therethrough. This causes a pressure diflerenti'al' to act on the diaphragm 56, the greater suction being applied to the'left-l'iand side of the diaphragm through the conduits 62 and 64, while the lesser suction is applied t'othe' other side through the conduit 58'. This causes the diaphragm 56 to move to the left against the force of spring. 66 and when a pre'- determined pressure drop has occurred this movement of omitted andthe'diaphragm 46 used only to unlatch the cover when no bag is'in' the cleaner.

In-the embodiment illustrated in Figs. 4', 5 and 6 the chamb erto'the right of the diaphragm 56infthe differential pressure responsive device 54' is provided with a port 112' communicating with the space within the cover 2'4and hence with atmospheric pressure. A- valve 114 isiprovi'de'd. for closing. this port and a spring 116" serves' to urge this valve towards open position and in contact Withtheinner side of plate 73; Pivotally mounted' on the outer side of plate 73 is a lever 118 having an intermediate projection 115 in contact with a part of valve 114 which extends through an opening in plate 73'. The lever is so positioned that if there is a paper bag in the cleaner; as shown in Fig. 4, when the cover 24 is'clo'sed the disc 76 of the bag strikes the free end of the lever and. pivots it in a clockwise direction so as to closetlrevalv'e'144. Likewise, if a cloth bag 1136 is in the machine, as'illustrate'din Fig. 5; the free end of the lever 11'8 strikes the flan'ge of the dust bag ring 103 when the cover is closed, thus forcing the valve 114 to closed'position. However, if no bag is in the cleaner, as'shown' inFi'g. 6, the leverllfi'strikes nothing and the spring 116 holds" the valve 114 in open position, thus connectingtlie space to the rightof the diaphragm 56 directly with the atmosphere.

Underthe latter condition, as the motor-fan unit is started; full fan suction is communicated through the conduits" 62and' 64 to the left-hand side of diaphragm 56. While" fullfan suction also exists in theinlet 60 to which is connected the conduit 58, nevertheless this has; littleornoetfecfon the right-hand side of the. diaphragm 56, dite'to the'fact'that' the chamber on this side of the diaphragm is open to the atmosphere and consequently atmospheric pressure is applied tothis side of thediaphragml Hence, thediaph'ragm is immediately moved to the left against the force of spring 66, thus opening valve 68 which permits the full fan suction to be communicated therethrough and through conduit 50 to diaphragm chamber 48. This causes the diaphragm 46 to be moved to the left to thereby release the latch 30 from engagement with the keeper 38, whereupon the rod 94 under the influence of spring 96 startsto open the cover 24 and at the same time shifts the switch 100 to the off position.

On the other hand, if either a cloth bag or a disposable bag is in position in the cleaner, the valve 114 is held in closed position, as previously described, and if the bag is clean substantially the same pressure will exist on both sides of the diaphragm 56 and hence the valve 68 will remain closed until, such time as the accumulation of dirt in the dust bag has increased the pressure drop therethrough to such a value that the resulting pressure 3 differential acting on the diaphragm 56 is sufficient to cause it to open the valve 68, whereupon the cover is unlatched and the motor stopped, indicating that the bag should be emptied or, if it is a disposable one, replaced with a clean one.

While I have described two more or less specific embodiments of my invention, it is to be understood that this has been done for the purpose of illustration only and the scope of my invention is not to be limited thereby, but is to be determined from the appended claims.

Certain subject matter disclosed but not claimed herein constitutes the claimed subject matter of my copending divisional application Serial No. 803,755, filed April 2, 1959.

What I claim is:

1. In a vacuum cleaner, a casing forming a filter compartment having an opening, a filter member introducible into said compartment through said opening, said filter member including an air-impervious portion, means for producing flow of air through said filter compartment, a closure for said opening, latch means for releasably securing said closure in closed position, pneumatically operated means for releasing said latch means, and a conduit extending from said pneumatically operated means to said compartment for connecting the former through said compartment with said means for producing flow of air, the end of said conduit being disposed so as to be closed by said impervious portion when said filter is in said filter compartment.

2. In a vacuum cleaner, a casing forming a filter compartment having an opening, a filter member introducible into said compartment through said opening, said filter including an air impervious portion, means for producing flow of air through said compartment, a closure for said opening, latch means for releasably securing said closure in closed position, pneumatically operated means for releasing said latch means, pressure responsive means operative upon a predetermined pressure drop through said filter member for connecting said pneumatically operated means with said means for producing flow of air, and a conduit extending from said pneumatically operated means to said compartment for connecting the former with said means for producing flow of air independently of said pressure responsive means, the end of said conduit being disposed so as to be closed by said impervious portion when said filter is in said compartment.

3. In a vacuum cleaner, a casing forming a filter compartment having an opening, a filter member introducible into said compartment through said opening, said filter member including an air-impervious supporting portion, means for producing flow of air through said filter compartment, a closure for said opening, latch means for releasably securing said closure in closed position, pneumatically operated means for releasing said latch means, control means responsive to a predetermined pressure drop through said filter member for connecting said means for producing flow of air to said pneumatically operated means, and a conduit for connecting said means for producing flow of air to said pneumatically operated means independently of said control means, the end of said conduit being disposed so as to be closed by said impervious portion when said filter member is in said compartment.

4. In a vacuum cleaner, a casing forming a dust bag compartment having an opening, means forming a seat around said opening, a dust bag introducible into said compartment through said opening and having an airimpervious supporting portion receivable on said seat, means for producing flow of air through said filter compartment, a cover for said opening hinged to said casing and pivotal to a closed position clamping said supporting portion against said seat, latch means for releasably securing said closure in closed position, pneumatically operated means mounted on said cover for releasing said latch means, and a conduit carried by said cover and connected to said pneumatically operated means, said con-' duit having an open end so disposed that, when said cover is in closed position, said open end is closed by contact with said impervious portion when said dust bag is in said compartment and communicates with said compartment and thereby connects said pneumatically operated means with said means for producing flow of air when said bag is absent.

References Cited in the file of this patent UNITED STATES PATENTS 2,322,948 Lofgren June 29, 1943 2,641,330 Lofgren et a1. June 9, 1953 2,656,897 Yonkers Oct. 27, 1953 2,742,105 Dow Apr. 17, 1956 

